Reds' former skipper criticises performance as "flat, with no urgency" and suggests some of those on the pitch shouldn't play for the club again

Former Manchester United captain Roy Keane took a shot at Michael Carrick and warned that some players will have no future at the club after the Red Devils suffered a painful 2-0 Champions League defeat to Olympiakos.

Keane also claimed the Reds' manager David Moyes would have been "shocked at the lack of quality" in the team he inherited from Sir Alex Ferguson last summer, and ridiculed the theory the Premier League is the strongest in the world.

Speaking on ITV, pundit Keane reacted sharply to a post-match interview from Carrick, who succeeded him in the United midfield in the mid-2000s, in which he seemed stunned by what he had experienced.

"That interview was just like the performance: flat. He should say a bit more, have a bit more urgency even in his interview," Keane said. "That just reflected United's performance tonight: Flat, with no urgency.

"They keep saying, 'Ah, well, next game, next game'. For some of them there won't be another game. That's the reality."

Keane was an on-field motivator in his playing days but he fears there is insufficient quality in the current United squad to make a serious impact in European football.

"I don't think any of us could have predicted that," he said after United's miserable surrender in the Athens district of Piraeus. "They (United) just never turned up. They (Olympiacos) were very, very good and technically they were better than United tonight."

Pressed on where United's problems this season have arisen from, Keane said: "There's a number of things: new manager, new ideas. United have missed out on some players over the past two years.

"There's some players playing tonight for Man United who just aren't showing enough quality."

He added: "I think United need six top quality players. I would think David Moyes has been shocked. I think when he went into United in the summer he probably looked at the players and was expecting great things.

"Privately, he's probably been shocked at the lack of quality he's working with."

United, Manchester City and Arsenal have all now suffered 2-0 first-leg defeats in the last 16, with Chelsea looking to avoid suffering such a disappointing outcome when they face Galatasaray on Wednesday.

Keane claims expectation of Premier League success in Europe is misguided.

"We've been brainwashed by this 'Premier League is the best league in the world' (talk)," Keane said. "Nonsense. It's the best brand, but we've seen over the past few weeks with a lot of the English teams struggling that these teams have fallen behind the top teams in Europe, and United in particular."

Carrick had said United can still progress but admitted the Greeks were in "a great position".

"It's hugely disappointing but we feel like we're still in with a chance going back to Old Trafford," he told Sky Sports 2. "Obviously it's not going to be easy.

"We've lost a game we came here hoping to win and haven't done that. We're not out of tie by all means, but it's not ideal."

Asked what went wrong on the night, Carrick added: "I'm not sure. We had good possession in the first half. We had control of the game without penetrating their line, but at same time they weren't causuing us any problems.

"The goals came from nothing, but it obviously puts them in a great position. We didn't start the second half very well. A bit sloppy, really."

Robin van Persie missed a glorious late chance to snatch an away goal, but Carrick did not want to point fingers at the Dutch striker.

"You can't blame Robin; he's created his chance and nearly scored," he said. "As players we have to stand up and take it on the chin.

"That's the business we're in. You take the good times and the bad times. We have to keep trying.

"You're looking for me to blame someone. As players we haven't been getting good results and as a club that's everyone involved. That's how we are judged."